1. Field of Invention
The present invention relates to a safety switch, and more particularly to a safety switch that can cut off a current circuit when an electrical current on the current circuit is overhigh.
2. Description of the Related Art
A safety switch is provided in a distribution box to prevent a high electrical current from causing an accident. The safety switch is composed of a shell, a first conducting strip and a second conducting strip mounted in the shell, and a bimetal strip securely mounted on the first conducting strip. The bimetal strip is made of two metal plates having different thermal expansion coefficients, is electrically connected to the second conducting strip.
Whether do functions of the safety switch achieve is dependent on the flexibility of the bimetal strip. In a conventional safety switch, a button presses against the bimetal strip. To separate the bimetal strip from the second conducting strip, a distortion force provided by the bimetal strip due to the heavy current has to be bigger than a biasing force applied by the button to the bimetal strip. If the biasing force provided by the button is large, the distortion of the bimetal strip will not be immediately and a product will be damaged because of the heavy current not being timely interrupted.
With reference to FIG. 10, a conventional safety switch has a base (60) with a fastener and a cover (70) with a fastener (71). The fasteners are respectively formed from the base (60) and the cover (70). However, the conventional safety switch has two disadvantages:
1. The base (60) and the cover (70) have to be made by a heat- resistant material to endure high temperature, but to reduce the resilience of the fasteners (71) of the base (60) and the cover (70). When the safety switch is assembled, the fasteners (71) are pressed and are easily broken.
2. The conventional safety switch is mounted merely in a specific panel and has a low practicality.
To overcome the shortcomings, the present invention provides a safety switch to mitigate or obviate the aforementioned.